In marine seismic exploration a seismic source emits sound waves which are reflected/refracted by interfaces between layers of the subsurface with different elastic properties. The amplitudes and arrival times of the returned sound waves are recorded by seismic sensors. Two main techniques are used to record the returned sound wave signals; one is by using hydrophone cables that are towed behind a vessel near the sea level, the other is to deploy seismic nodes containing the sensors at the ocean bottom. This invention relates to the latter technique.
After the seismic data has been recorded by the seismic nodes at the sea bottom, the seismic nodes are retrieved for transferring the seismic data to a data storage unit.
U.S. Pat. No. 7,883,292 describes a method and apparatus for storing, deploying and retrieving a plurality of seismic devices. The apparatus includes a ramp device coupled to a portion of a trailing end of a vessel, a cable handling device positioned between the ramp device and a leading end of the vessel to define a cable path across the ramp device, and at least one conveyor system having a first end located adjacent the ramp device and a second end extending toward the leading end of the vessel.
U.S. Pat. No. 4,458,621 describes a marine life harvesting method and apparatus in which a vessel has a marine life capturing device. A conveyor moves marine life from the marine life capturing device to a processing station.
WO 2011139159 describes a method for deployment of an ocean bottom seismic cable comprising seismic node casings containing autonomous sensor capsules, the method comprises deploying the ocean bottom seismic cable at the sea bed from at least one reel arrangement on a vessel, and automatically or manually inserting the autonomous sensor capsules into the seismic node casings before the seismic node casings are deployed into the sea. The autonomous sensor capsules may be inserted into the node casings by an industrial robot. It is also described a method for recovery of an ocean bottom seismic cable comprising seismic node casings containing autonomous sensor capsules, the method comprises spooling the ocean bottom seismic cable onto at least one reel arrangement, manually or automatically removing the autonomous sensor capsules from the seismic node casings during spooling, and retrieving the seismic data from the autonomous sensor capsules. The sensor capsule is placed in a docking station for unloading of data and recharging of batteries. This may be done by removing a battery and data storage unit from the sensor capsule and place it in a docking station, which may be managed by an industrial robot. The battery and data storage unit may further comprise a removable unit, comprising a real time clock, a CPU board and a memory. The removable unit may be docked by an industrial robot.
The purpose of the invention is to provide more refined technical solutions for the sensor capsules and their inner components and their handling.